The proposed research will examine whether the striking changes in catecholamine function observed during development in brain areas involved in vocal learning and/or the motor control of vocalization contribute to vocal learning and/or the differentiation and development of these brain areas. Study 1 will examine whether the use of catecholamine receptor antagonists or agonists during the period of vocal learning affects the ability to learn from a tutor, the type of receptor(s) involve, and whether drug treatment is more effective if done during the initial period of song memorization. It will also determine if such treatment causes gross changes in brain anatomy. Study 2 will investigate the effects of treating adult males with catecholamine receptor antagonists which decrease song learning to determine their immediate effects on males' singing and sexual behavior. Many of the effects of catecholamines are attributed to their effects on GABA and glutamate. Study 3 will determine whether levels and turnover of GABA and levels of glutamate change over the period of song learning and sexual differentiation of the brain areas which control singing behavior. Study 4 will examine whether early social deprivation regards the development of brain catecholamine function and levels of GABA and glutamate and whether these neurotransmitters are affected by juveniles' first interaction with a potential vocal model, suggesting an involvement in memorization of the vocal model. A major aim of this proposal is to help my colleagues in the Behavioral Neuroscience Group to meet their goals to become more productive researchers. Our formal mentoring program involves training in modern neuroscience techniques assistance in improving scientific communication skills, and specific training in writing focused grant applications. The issues addressed by this research are relevant to problems of human brain function and behavior. This research will possess possible contributions of several neurotransmitters to the development of a complex social behavior. It will also look for evidence suggesting that catecholamines are involved in stimulating some of the dramatic neuroanatomical changes which occur in brain areas controlling vocalization during the development of this behavior. Disruptions of catecholamine function have been implicated in a number of mental disorders in humans. Data providing a clearer picture of the normal involvement of brain catecholamines in the development of vocal communication in the development of vocal communication and soci8al behavior as well as the effects of experimentally induced disruptions of catecholamine function on behavior should be useful to those attempting to understand how neurotransmitter function affects behavioral and neural development.